The instant invention relates to a storage device and to a process for the storage of a limited length of yarn spun on a spinning machine, with a suction pipe connected to a negative-pressure line to seize and guide the yarn by means of suction air, and with a yarn storage chamber located between the negative-pressure line and the suction pipe, into which the yarn can be aspirated, and from which it can again be drawn off in a direction opposite to the direction of aspiration, as well as for the cleaning of the device and for keeping the suction air stream from the suction pipe.
Yarn storage devices of known types are used with yarn processing machines such as winding machines, weaving machines, or spinning machines with high yarn draw-off speed, for example, such as is the case with rotor, friction or air spinning machines. These spinning machines require yarn storage during piecing or repair of a yarn breakage, which is capable of holding a great length of yarn. During the period of preparation of piecing or yarn breakage repair, a great length of yarn is produced which must be stored in intermediate storage.
The storage of the yarn must be made in the smallest possible space since only limited room is available on the spinning unit or in the piecing carriage. In storing the yarn, provisions must be made to ensure that the yarn can be drawn off again at the required point in time easily and free of kinks and without yarn breakage. Yarn breakage during the draw-off process occurs if the friction at the wall of the yarn storage chamber becomes too great, or when tangled yarn layers have formed and hinder the drawing-off of the yarn, due to excessive layers and the formation of snarls.
Known yarn storage devices consist of suction pipes which seize the yarn by means of the suction air stream and draw it into the suction pipes (see German Patent No. DE-AS 2,802,913). Here, the suction pipe must have the same length as the yarn to be stored. Bends in this suction pipe, which would considerably reduce space requirements, have a detrimental influence upon the retention power exerted upon the yarn and increase the previously mentioned danger of yarn breakage.
In yarn storage devices made in form of a screen (German Patent No. 2,255,486, German OS No. 1,574,431), the screen surfaces must be cleaned very often because the screen openings become clogged with fibers and other impurities. As the screen surface becomes more and more dirty, the suction surface decreases and a constant storage capacity is no longer ensured in the yarn storage device after yarn storage.
It is a further disadvantage of yarn storage by means of screens of conventional design, that when a yarn breakage occurs in the yarn storage device, the broken yarn end is seized by the suction air stream and is sucked against the screen surface. This results in clogging up the screen surface so that a further piecing process can only be carried out following a time-consuming cleaning process.